Looking to fit a Mod 48 .22 mag cylinder to a Mod 17 3/8".22 L.R. cylinder revolver. The best of both worlds. Will it work..Your knowledge and experience is welcomed. Thanx George K ...

George,

I fit a new production model 648 cylinder to my 60's era model 17. The new cylinder came from Numrich's with a new, uncut extractor.

Fitting included a new center pin and cutting the new ratchets, but otherwise, tolerances were spot on and everything went very smoothly. I couldn't find a new model 48 cylinder, or afford a new or used model 48 at the time. (or now)

Amazing that the tolerances have not changed one iota over the approximately 60 year time span represented here.


Certainly no problem telling which caliber the gun is set up for now.......

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Ret. LE, FA Instr, S&W Armorer

Armorer951,
Thank you for your knowledgeable answer. I have heard several different scenarios as to fitment. From cylinder bore too small, barrel and forcing cone too tight, and lockup. Good to know a 686 cylinder will fit. Nice Look. Did you have to do anything with the yoke and ejector rod and star ??? I would love to try this approach based on your hands on experience.. I will look for a cylinder in .22 mag. NICE JOB on that project, Congrats.!! I wish I had that kind of knowledge...Would S&W sell me a #686 cylinder with rod and star. ??? Any help and advice will be greatly appreciated.. Thanx again for your help... Best; George K.

Sorry.. 648... And thanx again..

I'm not sure if S&W would provide and fit a new 648 .22 Magnum cylinder to your existing model 17. I doubt if they would, since the finishes don't match, and production "convertables" per se, were not offered, as far as I know....although there are probably some floating around. Numrich has the new cylinders in stock. The new cylinder will come with a new uncut extractor.

My model 17 is an older one, but there were no problems at all with the yoke or the cylinder assembly. Fitting only involved minor tweaking of a new center pin, and cutting the extractor ratchets to fit. The old extractor cannot be placed into a new production cylinder due to the design changes in the extractor itself. Any trained and experienced gunsmith could fit the 648 cylinder for you.....for a small fee, of course.

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Thank you for your help and information..My Model 17 is also early production... I found the s/s cylinder at Numrich new. What other parts should i need.?? Spring, collar etc. What has to be done to the extractor ratchets and new center pin ?? Does the extractor rod have to be shortened or the one that comes with the cylinder will fit properly ??"8 3/8 barrel fitment. I will have to find a machinist to cut the extractor ratchets.. Thanx...George K.

Your response to S&W doing the work makes sense..

You will need a new center pin, since you have an older model 17. The shoulder on the newer center pins is in a slightly different position, so the old pin won't work properly in the new cylinder. The OAL of the new center pin will also have to be fit to the front locking bolt. (for proper length)
All of the other parts, including the extractor rod, extractor rod collar, and the springs should work fine with the new cylinder.

The ratchets on the new cylinder's extractor will have to be cut (fit) to work properly with your particular gun. I would recommend finding a good, reputable, revolver gunsmith to fit the extractor as the work requires special tools and considerable experience.

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Ret. LE, FA Instr, S&W Armorer

Thank you again for your help... Best...George K.

ARMORER951...Called S&W today regarding fitment for a #648 .22 mag cylinder to a #17(.22lr). Too much liability for them to do the fitment..Not interested.... Are there any members in the forum who can do this fitment with the knowledge, experience, and tools for this project.?? I have to find a knowledgeable gunsmith, so I will start here on the Forum first. Thought you might have someone you know in the Forum who can do the fitment..... Thanx again... George K.

George,

I'm not aware of anyone here on the forum doing this sort of conversion. My recommendation would be to call several of the reputable gunsmiths and shops to see if they think it's feasible, and to get an estimate of the cost for the work.

I would check with Mark at Pinnacle High Performance, Cylinder and Slide, Hamilton Bowen, and Clark Custom. Perhaps some other members here on the forum will have more information for you.

If you decide to have the work done, please let us know how the project turned out. Thanks.

Carter

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Ret. LE, FA Instr, S&W Armorer

You could also try Andy Horvath in Lagrange, Ohio.
440-458-4369

Thank you all for your responses

armorer951
Carter,
Was your 648 cylinder 6 shot or 8 shot..recessed ???? S&W made both.. Thanx again George K.

It is the new production 6 shot from Numrich. Comes with a new, uncut extractor. All of the .22 cylinders are recessed.

Cylinder, .22 Mag, 6 Shot, Stainless (w/ Extractor) | Gun Parts Corp.

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Bob Cogan is in AL, so it wouldn’t cost an arm and a leg to ship it to him.

Accurate Plating & Weaponry | Gunsmith In Newville, Alabama

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Sure you did

Thank you Carter,
I called Numrich and was told the 648 cylinders are 1.61" long and the older 17 recessed and 1.68"long, So the newer 6 shot S/S cylinders are shorter.... Confused.. 648 S/S cylinders are recessed ??? Diameters the same...1.44" And you had no problem with lockup, headspace, and cylinder gap ??? I would suspect the shorter length of the 648 takes up the difference on the rim of the cartridge...Just a wild guess (probably wrong). But if the 648 cylinder is recessed my theory is wrong... Thanx... George K.

I'm doing the same modification that Carter did to his Model 17 to my pre-18. The only real problem I ran into was the diameter of the gas ring on the new 648 cylinder was larger than on my pre-18 and so I filed the barrel flat on the bottom of the barrel to gain clearance. Other than taking .002 off the yoke tube of the pre-18 it became a drop in fit. That .002 is easily taken up with a .002 shim in the pre-18 cylinder. I'm waiting for my new center pin, extractor rod, collar and springs to show up and then I'm going to cut the ratchets. I'm really looking forward to having a convertible pre-18. In process photo below.

Stu

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Amazing to me that the tolerances are still so close on these components after so many decades. One of the many things that make these guns so much fun to work on.

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stu1ritter,
Nice work....... Best...George K.

George,

I'm puzzled about the statements that the Numrich rep made in terms of the specifications and length of the cylinder itself. My new 648 cylinder from Numrich measures 1.623". The cylinder in my 60's era model 17 measures 1.620". All of the "rimfire" cylinders, including the 22 magnum cylinders are recessed.

In terms of fitting, and aside from the gas ring discrepancy, the cylinders are basically the same. There is the added burden of individually fitting/cutting each of the ratchets, but other fitting issues that came up were easily accommodated, as Stu has stated above.

Carter

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armorer951
Carl, Thanx for the measurements on the .22 LR and .22 Mag cylinders..You have answered my next question about cylinder measurements... I suspect the c/s reps at Numrich have limited information, maybe not. I have made progress on finding several Knowledgeable, hands on experience, and fairly reasonable gunsmiths who have done this procedure. The only problem they ALL had was the cylinder lengths from Numrich
648 mag 1.61"... LR..1.68".... Obviously wrong numbers from Numrich..Thanx for the response...Best; George K.

[QUOTE=georgek472;140943929]stu1ritter,
Nice work....... Best...George K.[
Stu,
Any thoughts on bore diameter .22lr vs..22mag. Thanx..George K

George,

Reference cylinder and pressure measurements, see post 7........


Impractical ?

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Here are the spec's..........I haven't given it all that much thought.

.22LR Bullet dia. .2255, bore dia .217, groove dia. .222
.22Mag Bullet dia .2245, bore dia .219, groove dia. .224

I'm not too concerned.

Stu

Nice work....... Best...George K.[/QUOTE]
Stu,
Did you have to shorten the injector rod ?? Or the one that came with cylinder was the right length...Thanx.. George K

The cylinder came with the ejector and that was all. I had to order the ejector rod, center pin, collar, center pin spring and ejector spring (about $25.oo). I'll fit them when I get them this Saturday (according to Brownell's). Those are pretty simple to fit.

Stu

[QUOTE=stu1ritter;140945244]Here are the spec's..........I haven't given it all that much thought.

.22LR Bullet dia. .2255, bore dia .217, groove dia. .222
.22Mag Bullet dia .2245, bore dia .219, groove dia. .224

I'm not too concerned.


Thank you for your response.. This "hands on"info will go a long way.. Thanx..... George K.

Stu,
Thank you for the "hands on" numbers...They will go along way in my efforts....Thanx again....George K.

[QUOTE=stu1ritter;140946414]The cylinder came with the ejector and that was all. I had to order the ejector rod, center pin, collar, center pin spring and ejector spring (about $25.oo). I'll fit them when I get them this Saturday (according to Brownell's). Those are pretty simple to fit.

Stu, Thanx again for your help.... Please let me know when you can, about the ejection rod once you have it fitted. It would be nice to have the rod fit as is...Good luck with your install....
Best; George K.

George, parts showed up from Brownell and are fitted. While all the instructions say to not shorten the center pin, I had to. Not much about .030" and the ejector rod had to be shortened slightly and chamfered on the inside to make it easier for the ejector rod end to pass off the locking bolt when opening. It was a quick touch of the center pin on a fine grinding wheel and then polished on emery paper. Slight chamfer on the locking bolt end of the center pin. Probably took 15 minutes. I'll start cutting ratchets tomorrow.

Stu

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stu,
Thanx for the pic...looks awesome... Looks like fitment, including ejector rod was successful..Congrats. After reading your post, seems like ejection rod fitment is relatively easy. I will have my parts from Numrich,and Brownells the upcoming week... I hope your complete install goes well... Looks and sounds rewarding after all your work. Thanx again for your info. Best to you..George K.

All done. As Carter said, I lucked out. I put a spot of Dykem on the ratchet face and scribed a light line through the frame hand window on the inside vertical face which would be where the hand would pass the ratchet tooth as it was cycling into place. When I took the cylinder out there seemed to be very little material to remove so I just took a few file strokes and put it back in to check and the hand almost cleared the tooth. Did it again and it cleared and worked. I did the other 5 ratchet teeth and put the gun together and with some empties in the chambers cycled it through twice in double action. A little stiff on two chambers but that will clean up when I stone the teeth smooth from the filing. Took it to the range and fired half a box of 50 CCI HP-V rounds. There is a nice blue flame at the muzzle of this 4" pre-18 with these rounds. This was a very enjoyable project and a great learning curve. Ratchets and timing always seemed to scare me away but after doing one, it is pretty straight forward. Kuhnhausen's shop manual has a lot of info on ratchet fitting and timing for anyone contemplating this process. Thanks Carter.

Stu

Excellent work. Glad it worked out for you and that you gained some experience on the project. When I cut the ratchet teeth to fit a recessed model 29 cylinder that had been reamed to 45 colt I was nervous in the beginning , but itt worked out.

To me working on them can be as interesting as shooting them. In fact I spend more time tinkering that shooting.

Congrats Stu,
Thanx to you and Carter I feel more comfortable with my fitment knowing that this procedure has been successfully completed by two (2) members here. I hope to get lucky with my install, which will happen in a few weeks. Waiting on Numrich and Brownell's for parts... Thank you all for your help and information...Best George K..

Stu. I ordered 2 extractor rods from Brownells, (Numrich had nothing in stock). The ones I ordered are both too short.
#940 074 830--- bbl over 3"
#940 070 500 --- bbl over 2 1/2"
Would you know the correct p/n ??
Brownell only lists the above 2 items.
My #17 is 8 3/8' barrel...
Thanx Again for your help...George K.

The part I ordered was S&W 070050000/Brownell 940-070-500WB which is the correct number for the 648. The other number you ordered seemed to be for stainless N frame revolvers. In my S & W parts catalog (factory) the only stainless extractor rods shown for 617 are the 070050000 which you have and the 077590000 which Brownells shows as their 940-000-241WB Extractor Rod, Glass Beaded, SS.

Is your model 17 a left hand threaded extractor? Does that rod fit?

Stu

Good morning Stu,
Thank you for your response regarding the correct p/n for the extractor rod.. I I suspect the rod is left handed thread if that is standard for that item from S/W..Still trying to remove from cylinder without damaging the knurling... I will try again or I will call S/W....
Sorry to respond late to your message I ve been fighting the Flu.. Thank You again for your help...Best; George K.

Stu,
Was able to loosen the extractor and fit the new s/s #648 extractor... It fits properly and locks into place. Guess I got lucky !!..... George K.

I would have thought that the 070050000 was the right one for your K frame. That is the correct part number for the 648 K frame who's cylinder we are using. Sounds like you didn't have to do any end fitting at all. Nice.

Stu

Stu,
Was able to loosen the extractor and fit the new s/s #648 extractor... It fits properly and locks into place. Guess I got lucky !! Left hand threads..... George K.

Thanx for the RIGHT information... George K.

Stu, hope you don’t mind that I jump into the conversation, but I have an 18-3 I would like to convert also. I have a 648 cylinder (with extractor only), and a 17 cylinder complete with yoke, extractor rod, center pin and both springs.

I’ve been following your posts, and I’m about to order the extractor rod, center pin, collar, and both springs from Brownells and Numerich, neither site had all the parts.

Hopefully not too stupid a question, but can I use the 17 yoke to complete the assembly? It does not appear to seat flush with the front of the cylinder. In the 17 cylinder it does fit flush, was this what you mentioned grinding down very slightly?. I haven’t tried, but assume I would have the same issue with the 18-3 yoke.

I cannot use the other 17 parts, since the extractor rod has right hand threads (I was able to take it apart), and I assume the 648 is left hand.

Thank you very much for all the detailed information, been a pleasure to read and follow your project.

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Danny
SWCA #3370 - SWHF #672

NavySCPO, I used my pre-18 yoke without problem and correct it will not seat flush. The diameter of the gas ring would rub on the bottom of the barrel on my pre-18 and so I had to increase the size of the flat on the bottom of the barrel to gain clearance. The fact that it doesn't seat flush doesn't matter on the yoke doesn't matter at all. When you have all of your parts together, test fit it and see where you are.

Stu

Stu

Thanks Stu, much appreciated. Hope mine turns out as well as that one of yours, make a great walking in the woods gun.

Danny

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Danny
SWCA #3370 - SWHF #672

Hello again,
Armorer951(Carlton) & Stu1ritter (Stu).
I have received all my goodies from Henrich & Brownell's this past week and found the s/s .22 Mag cylinder had been used and returned to Numrich, several scratches and worn areas around the ratchets and the opposite end (forcing cone). I returned and Numrich replaced cylinder with a nicer replacement.
My concern is that Numrich says 2 cylinder pins needed, they are no holes pre-drilled in the cylinder, under the star to fit the 2 pins.
I mentioned this to Numrich in the return letter describing my concerns, asked why 2 pins are needed on your website if there is no pre-drilled holes to accept the 2 pins.. No answer..
My question to Carter and Stu, did your parts come with pre-drilled holes for the pins, or installed cylinder without pins in place. or drill your own holes..???
Thanx again for all your help..George K.

Mine did not come pre-drilled for pins and it totally escaped my attention so I installed the cylinder without pins. I guess I have to look into this. It would be simple enough to do.

Stu

Jist tossing this out there, but my 648 cylinder has a flat on the shaft instead of pins like on my 17.

Certainly no gunsmith, but I assume the pins were to keep the extractor star aligned, so I’m guessing the flat eliminated the need for the pins, correct?

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Danny
SWCA #3370 - SWHF #672

Yes sir, that's correct. Extractor alignment pins are no longer needed or used. The flat on the extractor shaft serves the purpose of keeping the extractor in proper alignment..... along with the casings that are present inside the chambers.

BTW, empty casings should be used to align the extractor when the ratchets are marked and cut. This eliminates any gauge present in the assembly as the ratchets are fit/cut, and helps to keep the barrel and individual chambers aligned. (final cylinder timing)

Carter

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I checked the two revolvers I own that use the later ejector with the flat and neither is pinned from the factory so, as Carter said, we are good to go.

Stu